Certain nematic elastomers have optomechanical capabilities. It has been shown that certain nematic elastomers have the property of being able to change their shape by up to 400% in a relatively narrow temperature range. Further, it has been demonstrated that if the nematic order is suppressed, certain elastomers demonstrate mechanical responses in response to optical signal application on the elastomer.
As disclosed in the Physical Review Letters by Finkelmann and Nishikawa in their article “A New Opto-Mechanical Effect in Solids,” Physical Review Letters, Vol. 87, Number 1 (Jul. 2, 2001), which is herein fully incorporated by reference. They demonstrate optomechanical effect on photoisomerizable molecular rods which absorb light when illumination occurs on polarization along the polarization direction. At present, the only disclosure of movement of such materials lateral displacement within a body of fluid.
Finkelmann et al. note that the order parameter, back reaction and other related dynamic parameters may determine the rate of photoisomerization depending on the polarization of the rods in the nematic elastomer,
Potentially, the discovery may result in a rubber-like liquid crystal which changes shape when placed in a beam of light, the crystal seems to swim away from the point of light impingement. The molecules in the liquid crystal line up in one direction and in the electric field of a laser the rods compress the surface of the material.
Finkelmann et al. have shown that when an azo dye is applied to the nematic elastomer the molecules in the nematic elastomer tends to line up in one direction. When a nematic liquid crystal is applied an azo dye, the dye molecules “fold up” when they absorb light.
Referring to FIG. 1, there is shown a schematic diagram of a nematic liquid crystal with an azo dye applied. A light of wavelength λ is incident on liquid crystal 10 in FIG. 1(a). Referring to FIG. 1(b), the dye molecules, in reaction to the incident light applied on liquid crystal 10, “fold up.” Referring to FIG. 1(c), the dye molecules enable the liquid crystal 10 to speed up and avoid the light while losing the contraction. The liquid crystal 10 speeds across a direction 15.
The nematic elastomer additionally has the capability of accelerating motion proportional to the intensity of the light.
Although the discovery of the light avoiding properties of the particular liquid crystal has been surprising, there remains a need for practical applications of such light or laser movable liquid crystal (“LMLC”).
The LMLC is an elastomer liquid crystal that moves in response to an illumination that moves in response to a laser movement or light source. The LMLC is on the order of micrometers. The LMLC may be formed in different shapes, such as rectangular, elliptical or longitudinal.